The invention relates to a transmission system comprising a transmitter which includes a coder for coding an information signal to be transmitted into a digital signal constituted by the information signal and a redundancy signal, the redundancy signal being generated by way of a cyclic code from the information signal to be transmitted, and comprising a receiver which includes a decoder with a storage unit for storing a received information signal and with an error correction means which comprises a feedback shift register for processing the received digital signal.
The invention also relates to a receiver, a decoder and a videophone comprising such a decoder.
A transmission system of this type is used, for example, in video communication for videophones. In the receiver a decoder is then necessary, for example, for decoding a digital signal coded with the what is commonly referred to as BCH code (Bose-Chandhuri-Hocquenghem). A digital signal coded in this manner is used, for example, for video communication. During the coding procedure, an information signal to be transmitted is converted by means of a coding circuit into a digital signal that comprises the information signal as well as a redundancy signal. The redundancy signal is then generated by means of a cyclic code from the information signal to be transmitted.
U.S. Pat. No. 4,592,054 has disclosed a decoder in which a cyclically coded digital signal constituted by an information signal and a redundancy signal is applied to a random error as well as a burst error detection means which operate in parallel and independently. With the aid of a decision means either the output signal of the random error detection means or the output signal of the burst error detection means is switched to the output of the decoder.